The current trends toward increased efficiency, environmental friendliness, and higher quality longer life products makes the transition to LED based lighting more and more prevalent. The use of LED lighting in automobile lights, traffic lights, and even incandescent light replacements is a growing trend. There are a number of reasons the use of LED lights has not been used as an alternative to fluorescent lamps including the inherent efficiency of fluorescent lamps. Typically, fluorescent lamps have a life of about 6000 hours. The LED replacement lamps would have a life of 30,000 to 50,000 hours. During the life of LEDs the output can be held constant avoiding the degradation in light and flickering seen in fluorescent lamps. Additionally, fluorescent lamps provide a soft uniform light which is particularly advantageous in applications such as vending machines. The use of incandescent or even LED lights are generally not used in vending machines as having consumers look into these light sources is uncomfortable and tends to be blinding, which would make viewing the products to be vended more difficult. Looking into fluorescent lights does not generally have this effect, and hence improves the viewing of products. The present invention allows the use of LEDs while maintaining the advantages of fluorescent lighting. The present invention also takes advantage of the directional characteristics of LEDs to provide more useful light output where it is needed further improving the efficiency of the system.
The use of the present invention as a replacement for fluorescent lamps has a number of additional advantages. The current EU RoHS Directive banning the use of environmentally problematic materials currently provides an exception for fluorescent lamps. Without the exception, these lamps would not meet the requirements due to the levels of mercury used in the manufacturing and required for the operation of these lamps. Therefore, the present invention provides an environmentally safe alternative to the conventional lighting used in many applications, and in particular vending machines.
The use of the present invention as a replacement for fluorescent lamps also addresses the increasing concern of safety and efficiency. In an effort to improve the power efficiency of fluorescent lamps, the industry has moved from conventional ballasts to electronic ballasts. Each of these has presented challenges and problems which still exist and are particularly notable in applications serviced by untrained personnel such as in vending machines. The conventional ballasts are inefficient. Electronic ballast are more efficient but considerably more expensive. However, they have been associated with a number of quality problems. These range from the annoying flashing of fluorescent lamps as they age and cannot correctly power on, to arcing at the lamp sockets especially when lamps are not correctly inserted resulting in the potential for fire. LED based lamps would eliminate these issues. Another key advantage of the lamp of the current invention as a replacement for fluorescent lamps is the LED lamps will not present a safety concern if dropped or broken. Fluorescent lamps implode when broken, shattering glass and the environmentally unfriendly elements housed within the lamps. LED lamps are based on solid state devices that have no such concern.
A key element to the current invention is that the LED based lamp can include additional electronics to allow these lamps to be mechanically and electrically compatible with existing fluorescent lamps. In these cases, the LED based lamps can be direct replacements for existing fluorescent lamps in applications such as current vending machines. This would allow most of the benefits of using the LED lamps to be realized without having to re-wire existing lighting systems or replacing existing ballasts. In most applications light is desired to be directed to an area limited to about 180 degrees or less. Standard fluorescent lamps emit light in 360 degrees which results in wasted energy or the requirement for reflectors to direct the light where needed. The current invention will direct light in a plane limited to about 180 degrees. To optimize the orientation of the LED lamp, adjustable pins used to secure the lamps into existing lamp sockets will allow the necessary flexibility to direct the light where needed.
The current invention also anticipates the ability to control the lighting rather than just have it on continuously and at full brightness. This is achieved by adding intelligence to the LED lamp so that it has a communications capability compatible with existing communication systems within the product or system with which the LED lamp is intended to be used. In the case of vending machines, this communications system can be MDB, RS232, DEX, infrared, inductive, RF, or the like. The advantages of providing such an intelligent lamp would be to allow the existing controller, such as the existing vending machine controller, to control the operation of the machine lighting through the existing communication links. This would allow the lamp to be turned on or off based on time, machine use, sensed approaching of consumers, or any such method. It would also allow the lamp to be dimmed, flashes, chased or any other special effects created as needed. One particular implementation of the current invention uses multiple color LEDs to allow the creation of different colored light to be generated also controllable through the communications link. The particular choice of Red, Green and Blue LEDs has the additional benefit of creating white light of selectable color temperature as well as the various colors achievable with the mixing of these primary colors. The use of color provides additional attention getting techniques to be applied which will aid in the marketing of the products that may be in a vending machine as an example.
In the case of a vending machine, the choice of MDB as a communications link is particularly attractive as this is the existing interface standard for all the peripherals in a vending machine. This includes the coin, bill and card readers. The protocol already exists and is supported through NAMA, the industry trade association. Adding specific enhancements to this interface to allow vending controllers to have the ability to achieve the control and leverage the features of the LED lamp would be a relatively simple process. The interface is not proprietary so any machine manufacturer would be able to take advantage of this new technology.
In the broader context, the control of the intelligent LED lamp can include a wireless interface such as RF, IR or the like. The use of wireless remote control opens the market options of providing efficient lighting to any environment so long as a source of power (low voltage or high voltage, AC or DC) is available. All the advantages of efficient control of the lighting (time based turn on and off, use based turn on or off, dimming and color generation) are achievable without having to rewire an existing facility or device.
The mechanical configuration of the LED lamp of the current invention is not limited to just the fluorescent tube arrangement. However, even for this arrangement, the LED lamps can be provided in fixed length “strips” which can be interconnected to provide various length lamps. For example, a 12″ lamp could be connected directly to a second 12″ lamp to provide a 24″ lamp. This stackable design would allow maximum flexibility using standard lamp modules.